H. Miwa et al., Effects of blockade of metabotropic glutamate receptors in the subthalamicnucleus on haloperidol-induced Parkinsonism in rats, NEUROSCI L, 282(1-2), 2000, pp. 21-24
The present study examined the postural effects of unilaterally local injec
tion of metabotropic glutamate receptor (mGluR) antagonists into the subtha
lamic nucleus (STN), in rats with haloperidol-induced parkinsonism. In rats
which received uni lateral microinjections of (+)-alpha-methyl-4-carboxyph
enylglycine (MCPG), a selective, subtype-non-specific antagonist of mGluR,
but not the vehicle, into the STN, systemic administration of haloperidol i
nduced ipsiversive dystonic posturing. The severity of the dystonic posturi
ng was dose-dependent. However, subtype-specific antagonists of group I, II
, or III mGIuRs induced no dystonic posturing. The present findings suggest
that the activity of the STN under conditions of dopamine blockade is faci
litated by blockade of mGluRs in the STN, suggesting that mGluRs exert inhi
bitory influence on glutamate release in the STN. (C) 2000 Elsevier Science
Ireland Ltd. All rights reserved.